Adoptive transfer of virus-specific T cells is a promising strategy for the prevention and treatment of viral disease.
Adoptive transfer requires the use of a large number of T cells. For example, Chia et al., Mol Ther (2014) 22(1): 132-139 describe treatment of EBV-positive nasopharyngeal carcinoma (NPC) by adoptive transfer of a median total number of 9.6×108 EBV-CTLs (ranging from 6.3 to 10.3×108 CTLs).
A major problem for therapy by adoptive T cell transfer is the period of time taken to generate sufficiently large numbers of virus-specific T cells for administration. Chia et al. (supra) reported that the median time taken to produce and the first dose of CTLs was 13 weeks (ranging from 8 to 22 weeks). Moreover, it is reported that in this study that for 3 patients there was deviation from the scheduled therapy due to delays in CTL production.